Found this great guide to performing some basic web tasks such as submitting forms, uploading files, and interacting with RESTful services.
The tutorial is from Core Animation book co-writer Matt Long, and can be found here: Accessing The Cloud From Cocoa Touch
In the tutorial Matt goes through using the Cocoa libraries to perform basic web tasks, and also talks a little bit about the excellent ASIHTTPrequest library. He also goes through some principles that you will want to follow when creating RESTful web services. This is a great read on the absolute basics of interacting with the web using Cocoa.
Please post any comments below, thanks.